The invention relates to a semiconductor substrate, a method for producing it and a method for producing a circuit module. The invention relates, in particular, to improvements in the bondability of power semiconductor substrates after processes.
In the further development of modern power semiconductor electronics, great importance is attached not only to possible miniaturization and improvement of functional reliability but also to simplifications in the area of the production methods, and the intention is for possible simplifications not to be obstructed by losses of quality.
In known production methods, semiconductor modules with semiconductor substrates on carriers have hitherto been produced by the finished semiconductor substrates being fitted on the surface of the carrier to be provided in each case and then being contact-connected externally. Between the actual production of the semiconductor substrate and the fitting and contact-connection by means of contact regions provided at the semiconductor substrate, that is to say between the actual production and corresponding placement methods in the formation of the modules, there may be considerable time intervals that have to be bridged by a corresponding storage process and/or transport for the semiconductor substrates once they have been produced.
It is now known that uncovered surfaces of the contact regions provided at semiconductor substrates are contaminated or exposed to a chemical conversion process, e.g., via oxidative attacks via the atmospheric oxygen provided in the atmosphere.
In known production and mounting methods, therefore, a protective gas atmosphere is provided, either during storage and/or during mounting or contact-connection itself. Forming and ensuring a corresponding protective gas atmosphere over a relatively long period of time means an additional outlay in terms of technical apparatus and also financially.
For these and other reasons, there is a need for the present invention.